1. Technical Field
The present invention relates to an optical waveguide device which is used in a mobile apparatus or the like and guides light as a waveguide, and to a light outputting module using the optical waveguide device.
2. Related Art
Examples of methods of fabricating an optical waveguide film as an optical waveguide device are: (1) a method of impregnating a film with a monomer, selectively exposing a core portion so as to change the refractive index, and laminating films together (a selective polymerization method); (2) a method of coating a core layer and a clad portion, and thereafter, forming the clad portion by using reactive ion etching (RIE method); (3) a method using photolithography which carries out exposure and development by using an ultraviolet-curing resin which is obtained by adding a photosensitive material into a polymer material (a direct exposure method); (4) a method using injection molding; (5) a method of coating a core layer and a clad portion, and thereafter, exposing a core portion so as to change the refractive index of the core portion (a photobleaching method); and the like. Further, when limited to a rectilinear waveguide, there are methods such as a method of fabricating the optical waveguide including forming a core portion of the optical waveguide by locally cutting and removing, by a dicing saw or the like, the layer which becomes the core and which has a high refractive index and is obtained by laminating two layers of resin having different refractive indices, and thereafter, covering the core portion with the same polymer resin as the clad portion, and the like.
However, in recent years, in IC technologies and LSI technologies, attention has focused on carrying out optical wiring between apparatuses and between the boards and between the chips within the apparatuses, instead of carrying out high density electrical wiring, in order to improve the operational speed and the degree of integration. In order to realize such optical wiring, surface emitting elements having an excellent high-speed characteristic and mass-production characteristic, and VCSEL elements in particular, are used for interconnection applications and applications for optical communications. However, differently than edge emitter elements, it is difficult to monitor the light output of a VCSEL element as a unit.
Thus, in elements at which a VCSEL element is packaged, a method is usually used in which a portion of light coming from a window for output is reflected, and this reflected light is used in monitoring the light output. However, reflecting and taking-out a portion of light coming from a window for output is inefficient, and excess current must be sent to the VCSEL element so as to increase the light output. At this time, excessively complex external circuits that also are needed as temperature control is required in order to avoid the effects of heat, or the like.